The LVT had its origins in a civilian rescue vehicle called the Alligator. Developed by Donald Roebling in 1935, the Alligator was intended to operate in swampy areas, inaccessible to both traditional cars and boats. Two years later, Roebling built a redesigned vehicle with greatly improved water speed. The United States Marine Corps, which had been developing amphibious warfare doctrine based on the ideas of Lt. ColEarl Hancock "Pete" Ellis and others, became interested in the machine after learning about it through an article in Life magazine and convinced Roebling to design a more seaworthy model for military use. After more improvements to meet requirements of the Navy (made difficult by Roebling's lack of blueprints for the initial designs) the vehicle was adopted as "Landing Vehicle Tracked" or LVT.

The contract to build the first 200 LVTs was awarded to the Food Machinery Corporation (FMC), a manufacturer of insecticide spray pumps and other farm equipment which built some parts for the Alligators. The initial 200 LVTs were built at FMC's Dunedin, Florida factory, where most of the improvement work had been done as well. Eventually the company became a prominent defense contractor, United Defense (now part of BAE Systems Land and Armaments). During the war LVT production was expanded by FMC and the Navy to four factories, including the initial facility in Dunedin; the new facilities were located in Lakeland, Florida, Riverside, California, and San Jose, California. Roebling Construction got the lucrative construction contract for the Lakeland factory: this was the only profit Roebling got from his invention, as he refused to accept any direct royalties or commissions from the government, seeing it as his personal duty in support of the war effort.

The LVT 1 could carry 18 fully equipped men or 4,500 pounds (2,041 kg) of cargo.[3] Originally intended to carry replenishment from ships to shore, they lacked armor protection and their tracks and suspension were unreliable when used on hard terrain. However, the Marines soon recognized the potential of the LVT as an assault vehicle. Armored versions were introduced as well as fire support versions, dubbed Amtanks, which were fitted with turrets from Stuart series light tanks (LVT(A)-1) and Howitzer Motor Carriage M8s (LVT(A)-4). Among other upgrades were a new powerpack, also borrowed from the Stuarts, and a torsilastic suspension which significantly improved performance on land.

Production continued throughout the war, resulting in 18,621 LVTs delivered. In the late 1940s a series of prototypes were built and tested, but none reached production stage due to lack of funding. Realizing that acquisition of new vehicles was unlikely, the Marines modernized some of the LVT-3s and LVT(A)-5s and kept them in service until the late 1950s.

The LVT were mainly used for logistical support at Guadalcanal, up until the development of the LVT-4 version which allowed for embarkation and disembarkation from a rear ramp, greatly improving combat utility by allowing troops to dismount from the vehicle much more quickly. Previous versions had no such means of entry or exit.

The first usage of the LVT in combat was during the amphibious assault on Tarawa in late 1943. Of 125 vehicles used, only 35 remained operational by the end of the day. Still, a number managed to successfully ferry men across the coral reef and through the shallows to the beach. Marines who arrived in LCVP "Higgins boats", on the other hand, could not cross the reef and had to wade through chest-deep or higher water while under enemy fire; casualties were horrific and many who did make it to the beach alive had lost their rifles and other essential gear. Despite their apparent utility however, the LVT-1 was too lightly armored for combat, and the open crew and passenger compartment resulted in serious injuries from both machine gun fire and shrapnel. The operation also revealed the need for close-in fire support, which the Amtracs lacked.

As a result of Tarawa experience, standardized armor kits were provided for the LVTs employed in contested landings, and the gun-armed "amtanks" LVT(A)-1 and LVT(A)-4 were developed to provide fire support. Armed with a 75 mm howitzer, the latter was especially effective in this role as it was capable of destroying Japanese fortifications as it came ashore. However the LVT(A)-4 had an open-topped turret which left the crew vulnerable to artillery and infantry attack, especially to the latter as it lacked any sort of machine gun armament. The lack of machine gun armament was eventually rectified, though the open-topped turret remained in order to save weight. Although usually used in a direct role during landings only (once inland the "amtanks" were assigned to artillery formations to augment their firepower), in the Marianas campaign "amtanks" were employed inland, much like regular tanks.

The largest use of the LVTs was in the Leyte landing, with nine amtrac and two amtank battalions deployed. As there was no fighting on the beaches, this is also one of the least famous LVTs operations. Over 1000 LVTs took part in the Battle of Okinawa.

Although usually associated with the Pacific theatre, toward the end of the war LVTs were employed in Europe as well. The U.S., British and Canadian armies used the Buffalo in the Battle of the Scheldt (1944), during the Operation Plunder crossing of the Rhine, along the Po River in Italy, across the river Elbe, and in a number of other river crossing operations.

In the 1950s LVTs still in service were replaced by the LVTP-5 family of vehicles, which in turn were followed by the LVT-7 family, eventually redesignated AAV. The AAV is manufactured by BAE Systems Land and Armaments, which was the first company to produce the LVT (as FMC).

In 1958 the US Navy tested the largest LVT ever produced, the LVT(U)X2Goliath produced by Pacific Car and Foundry. The Goliath was so large that it could transport from a landing dock ship to shore and across beach barriers any load the conventional LCU could, including a 60-ton main battle tank. Only one Goliath was built and it never became operational.[4][5]

Currently, many of the world's militaries employ more modern versions of the amtrack. One of the latest is the now cancelled United States Marine CorpsExpeditionary Fighting Vehicle, that was slated to begin replacing the AAV in 2015 but was cancelled in 2011 after going significantly over budget.

LVT-2 Water Buffalo with Marines bound for the beaches of Tinian Island, 1944

LVT-3

LVT-3C

The US Army used a different naming system from the Navy. Instead of using the usual Army system of Model or M-numbers, they referred to the LVTs by Mark number using Roman numerals rather than Arabic numerals. Hence the LVT-4 was the "Mark IV" (which was not the same as the "M4").[2]

LVT-1 (1941)

The first military model. Traveling at a respectable 6 knots in the water and 12 mph (19 km/h) on land, it could deliver 24 fully equipped assault troops to the beach, and supply supporting fire from two .30 cal M1919 Browning machine guns though it was only intended for delivering supplies inland until wheeled vehicles could be brought ashore. Many vehicles were refitted prior to the Tarawa landing to hold two .50 cal (12.7 mm) Browning heavy machine guns forward, with the .30 cal guns aft. The vehicle was not armored and its thin steel hull offered virtually no protection, although prior to Tarawa some vehicles received 9 mm of armor plating to the cab. Tracks performed well on sand, but not on tough surfaces. The rigid suspension threw tracks and roller bearings corroded in salt water.[6] Proper maintenance of the new machine was often an issue, as few Marines were trained to work on it, and early models suffered frequent breakdowns. 1,225 units produced.

LVT-2 Water Buffalo, British designation Buffalo II (1942)

Featured new powertrain (the same as that in the M3A1 light tank) and torsilastic suspension. The aluminium track grousers were bolted on making changes much easier since they wore out quickly on land and more so on coral. Hard terrain performance was much better compared to the LVT-1. 2,962 units produced.

LVT(A)-1 (1942)

Based on the LVT-2, A standing for armored, this fire support version had an armored (6 to 12 mm) hull. It was fitted with a turret nearly identical to that of the Light Tank M3, with a 37 mm Gun M6 in an M44 mount, and also carried two rear-mounted machine guns. 510 units produced.

LVT(A)-2 Water Buffalo (1943)

Armored version of the LVT-2. Capacity 18 troops. 450 units produced.

LVT-4 Water Buffalo, British designation Buffalo IV (1943)

FMC modified an LVT-2 in August 1943 by moving the engine forward and adding a large ramp door in the rear,[7] allowing troops to exit from the rear of the vehicle. Capacity went from 16 in the LVT-2 to 30 making earlier LVTs largely obsolete. This innovation also greatly facilitated the loading and unloading of cargo. Some vehicles received armor kits. It was by far the most numerous version of the LVT, with 8,351 units delivered. Many of the British LVT versions were armed with a 20 mm Polsten cannon and 2 × .30 in (7.62 mm) Browning machine guns.

Developed by the Borg Warner Corporation as their Model B in April 1943. To allow for rear loading, the engines were moved to the sponsons and a ramp installed in the rear. Some received armor kits. First used in Okinawa in April 1945. 2,964 units produced.

LVT(A)-4 (1944)

The 37mm gun of the LVT(A)-1 was inadequate for fire support version so the turret of the 75 mm Howitzer Motor Carriage M8 - armed with a 75 mm howitzer - was used to produce the LVT (A)-4. In some cases the 75 mm was replaced with the CanadianRonson flamethrower. A single .50 cal machine gun was installed on the ring mount above the turret rear. In the late production vehicles the heavy machine gun was replaced with two M1919A4 .30 MGs on pintle mounts and one more in the bow mount. 1,890 units produced. The Chinese PLA captured several from Nationalist forces during the Civil War and placed them in service, eventually modifying some with the 37 mm M6 tank gun (?) in place of the 75 mm howitzer and others with the ZiS-2 57 mm anti-tank gun, complete with shield, the conversion necessitating the removal of the original mantlet as well.

LVT(A)-5 (1945)

LVT(A)-4 with powered turret and a gyrostabilizer for the howitzer. Some were upgraded in the late 1940s by changing armor configuration. 269 units produced.

LVT-3C (1949)

Modified LVT-3. Armored roof was fitted and the bow was extended to improve buoyancy. Armament included .30 MG in a turret and .30 bow MG in ball mount. 1200 LVT3s were converted.

Amphibian, tracked, 4-ton General Service (1944/45)

A British vehicle based on the LVT-4 and known as the Neptune. Only a handful of the 2,000 ordered were completed. The Sealion was a recovery version, and the Turtle a workshop version.